Apparatus and method for warpage compensation of a display panel substrate assembly

ABSTRACT

An apparatus and method for warpage compensation of a display panel substrate assembly are described. A method and apparatus for warpage compensation of a display panel substrate assembly are described. In one embodiment, the method includes the selection of a substrate having a substrate warpage level exceeding a warpage tolerance level. Once selected, a plurality of conductive bumps are formed over an area of the selected substrate. Once formed, a thermal process is applied to the plurality of conductive bumps to obtain a virtual plane over the area of the selected substrate have a coplanarity level below a coplanarity specification level. As such, utilizing embodiments of the present invention, lower cost substrates with substandard warpage levels may be utilized to form OLED panel substrate assemblies when compensated utilizing embodiments of the present invention.

RELATED APPLICATIONS

[0001] This application is a divisional application of U.S. applicationSer. No. 10/302,282, filed Nov. 22, 2002, currently pending, whichapplication is a non-provisional application of U.S. Provisional SerialNo. 60/369,958, filed Apr. 4, 2002, now expired.

FIELD

[0002] One or more embodiments relate generally to the field of organiclight-emitting diode (OLED) displays. More particularly, one or more ofthe embodiments relates to a method and apparatus for warpagecompensation of a display panel substrate assembly.

BACKGROUND

[0003] Traditional liquid crystal displays (LCDs) are utilized asconventional display devices. Unfortunately, LCDs require backlighting,as well as diffusers and polarizers, since LCD displays are notself-luminous. Furthermore, the backlighting is generally provided bybulky and environmentally undesirable mercury lamps, which consumeinordinate amounts of power. Likewise, the lumination within LCDs oftengenerates undesirable amounts of heat and causes electrical interferencewithin attached electronic devices. As a result, LCDs generally requiresubstantial space and are often quite heavy.

[0004] In contrast, organic light-emitting diode (OLED) technologygenerally enables full color, full motion, flat panel displays, with alevel of brightness and sharpness not possible with traditional LCDs.Moreover, unlike traditional LCDs, OLEDs are self-luminous. As a result,flat panel displays utilizing OLEDs do not incur many of the problemssuffered by traditional LCDs.

[0005] An OLED structure, which is utilized to enable an OLED displaydevice generally includes organic carbon-based film layers between twocharged electrodes. A first electrode is commonly a metallic orconductive cathode, while a second electrode is commonly a transparentanode, generally made of glass. The organic film layers may comprise ahole injection layer, a hole transport layer, an emissive layer and anelectron transport layer.

[0006] In operation, a voltage potential is applied to an OLED structureto provide lumination within the OLED display device. When the charge isapplied, the injected positive and negative charges within the OLEDrecombine in an emissive layer in order to create electroluminescentlight. As a result, OLED displays emit light, in contrast withconventional display technologies, such as LCD displays, which modulatetransmitted or a reflected light.

[0007] An OLED structure may also include a ceramic panel and aconductive adhesive contact. In order to construct panels, such as OLEDdisplays, some kind of substrate, such as a ceramic, organic or metallicplate, is required. As such, the substrate enables assembly of an OLEDpanel that is constructed of glass or organic film in order to enableconnection to an electric circuit. However, in order to enable fullmotion flat panel displays, a warpage tolerance/coplanarityspecification value required of selected substrates is generally lessthan 30 micros per inch (micron/inch).

[0008] Unfortunately, the coplanarity specification required for OLEDflat panel displays drastically increases the cost to manufacturers ofOLED displays. In order to address the warpage tolerance coplanarityspecification requirements, manufacturers of conventional OLED displaysgenerally utilize higher cost ceramic substrates. Otherwise, themanufacturers utilize special treatments (polishing), which are appliedto ceramic substrates to reduce the warpage level of the substrate toconform to required tolerances. Consequently, conventional processes forenabling flat panel OLED display construction significantly increase thecosts of substrate material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The various embodiments are illustrated by way of example, andnot by way of limitation, in the figures of the accompanying drawingsand in which:

[0010]FIG. 1 depicts block diagrams illustrating a flat screentelevision (TV), as well as a flat screen monitor.

[0011]FIG. 2 depicts a block diagram illustrating an optical lightemitting diode (OLED) structure.

[0012]FIG. 3 depicts a block diagram illustrating an OLED display panelmodule.

[0013]FIGS. 4A-4C depict block diagrams illustrating warpagecompensation of a substrate.

[0014]FIG. 5 depicts a block diagram illustrating formation of an OLEDdisplay panel module utilizing a warpage compensated substrate.

[0015]FIG. 6 depicts a block diagram illustrating an OLED display panelmodule.

[0016]FIG. 7 depicts a flowchart illustrating a method for performingwarpage compensation of a selected substrate to enable usage of thesubstrate within an OLED display panel module assembly.

[0017]FIG. 8 depicts a block diagram illustrating a method for couplingan OLED panel to a warpage compensated substrate.

[0018]FIG. 9 depicts a flowchart illustrating a method for forming aplurality of conductive bumps over an area of a selected substrate.

[0019]FIG. 10 depicts a flowchart illustrating an additional method forapplying a thermal process to the plurality of conductive bumps toobtain a virtual surface.

DETAILED DESCRIPTION

[0020] A method and apparatus for warpage compensation of a displaypanel substrate assembly are described. In one embodiment, the methodincludes the selection of a substrate having a substrate warpage levelexceeding a warpage tolerance level. Once selected, a plurality ofconductive bumps are formed over an area of the selected substrate. Oncethe conductive bumps are formed, a thermal process is applied to theplurality of conductive bumps to obtain a virtual surface over the areaof the selected substrate have a maximum coplanarity level below acoplanarity specification level.

[0021] In one embodiment, the apparatus includes a substrate including aplurality of conductive bumps having a virtual plane with a coplanaritylevel below the maximum coplanarity specification level. The virtualsurface is formed by applying a thermal process to the plurality ofconductive bumps. An adhesive conductive layer formed over the virtualsurface. In addition, the apparatus includes an OLED panel layer coupledto the substrate via the adhesive conductive layer to connect electrodesbetween the OLED panel and the substrate. As such, utilizing embodimentsof the present invention, lower cost substrates with substandard warpagelevels may be utilized to form OLED panel substrate assemblies whencompensated utilizing embodiments of the present invention.

[0022] In the following description, for the purposes of explanation,numerous specific details are set forth in order to provide a thoroughunderstanding of the embodiments of the present invention. It will beapparent, however, to one skilled in the art that the variousembodiments of the present invention may be practiced without some ofthese specific details. For example, various substrates and conductivebump configurations may be modified according to the embodiments of thepresent invention to provide the desired virtual surface coplanaritylevel.

[0023] In addition, the following description provides examples, and theaccompanying drawings show various examples for the purposes ofillustration. However, these examples should not be construed in alimiting sense as they are merely intended to provide examples of theembodiments of the present invention rather than to provide anexhaustive list of all possible implementations of the embodiments ofthe present invention. In other instances, well-known structures anddevices are shown in block diagram form in order to avoid obscuring thedetails of the various embodiments of the present invention.

[0024]FIG. 1 depicts block diagrams illustrating flat screen TV 100, aswell as flat screen monitor 110. In contrast to conventionaltelevisions, as well as computer monitors, flat screen TV 100 and flatscreen monitor 110 are drastically smaller than conventional televisionsand monitors. However, flat screen TV 100, as well as flat screenmonitor 110, include a screen size, which is as large, if not larger,than a corresponding contemporary devices. Flat screen devices depictedin FIG. 1 have become a reality due to the use of, for example, opticallight emitting diodes (OLED).

[0025] As indicated above, traditional liquid crystal displays (LCDs)are generally not self-luminous. As a result, backlighting is requiredto illuminate the displays, which is provided by bulky environmentallyundesirable mercury lamps, which consume an inordinate amount of power.As a result, LCDs generally require substantial space, and are oftenquite heavy in contrast to the flat panel displays depicted in FIG. 1.In contrast, organic light emitting diode technology enables full color,full motion, flat panel displays with a level of brightness andsharpness that is not possible with traditional LCDs. Moreover, unliketraditional LCDs, OLEDs are self-luminous. As a result, flat paneldisplay modules constructed utilizing OLEDs do not incur many of theproblems suffered by traditional LCDs.

[0026]FIG. 2 depicts OLED structure 200, which may be utilized withinflat panel displays, as depicted in FIG. 1. OLED structure 200 generallyincludes organic carbon-based film layers between two chargedelectrodes. For example, OLED structure 200 includes glass substrate210, including, for example, transparent anode 220, generally made ofglass or indium-tin oxide (ITO). The organic layers comprise a holeinjection layer (HIL) 270, organic emitters 260, as well as electrontransport layer (ETL) 250. Likewise, OLED structure 200 includes metalcathode 240 above organic film layers (250, 260 and 270).

[0027] In operation, voltage potential 230 is applied to OLED structure200 in order to provide rumination within an OLED display deviceutilizing OLED structure 200. When the charge is applied, the injectedpositive and negative charges within OLED structure 200 recombine in anemissive layer in order to create electroluminescent light. As a result,OLED displays emit light, in contrast with conventional displaytechnology, such as LCD displays, which modulate transmitted orreflected light. As such, when voltage potential 230 of, for example,two ten volts direct current is applied to metal cathode 240 and anode220, light output 280 is generated from OLED structure 200.

[0028] Conventionally, OLED structure 200 may be utilized to form anOLED display module, for example, as depicted in FIG. 3. As illustratedin FIG. 3, OLED display panel module 300 is formed utilizing OLEDstructure 200, for example, as depicted in FIG. 2. In order to constructOLED display panel module 300, as depicted in FIG. 3, some kind ofsubstrate 310, such as a ceramic, organic or metallic plate is required.

[0029] As such, substrate 310 enables assembly of an OLED panel that isconstructed of a glass organic film in order to enable connection to anelectric circuit, for example, to provide a voltage potential betweencathode 240 and anode 220, to generate rumination from glass structure210. However, in order to meet the strict tolerances required tomanufacture flat panel displays, for example, as depicted in FIG. 1, awarpage tolerance/coplanarity specification value required of selectedsubstrates, for example, substrate 310, is generally less than 30 microsper inch.

[0030] Unfortunately, the coplanarity specification level required forOLED flat panel displays drastically increases the cost to manufactureOLED displays, such as flat panel TVs, as well as flat panel screen 120,as depicted in FIG. 1. In order to address the warpagetolerance/coplanarity specification requirements, manufacturers ofconventional OLED displays generally utilize higher cost ceramicsubstrates having a coplanarity level, which is at most equal to the 30micron per inch coplanarity specification value required for OLEDdisplay devices. Otherwise, the manufacturers utilize specialtreatments, such as polishing, which are applied to ceramic substratesin order to remove warpage from the substrates such that the finalsubstrate includes a coplanarity value, which is less than the 30microns per inch coplanarity specification requirement.

[0031] As a result of the warpage tolerance/coplanarity specificationrequirements for substrates utilized within OLED display panel modules,flat screen TVs, as well as monitors, utilizing OLED display panelmodules are often quite expensive. As indicated, substantial costs arefurther exacerbated by finding substrates which comply with thecoplanarity specification requirements. However, in order to combat thecoplanarity specification requirements for OLED display panel modules,FIGS. 4A-4E illustrate an embodiment for performing warpage compensationof a substrate to enable usage of the substrate within an OLED displaypanel module assembly.

[0032]FIG. 4A depicts substrate 410, which has an undesirable warpagelevel, which may be in the range of 60 microns per inch through 700microns per inch. Conventional coplanarity specification requirementsare generally, at most, 30 microns per inch, which is quite uncommon insubstrate materials used widely in the semiconductor industry. Suchsubstrate material includes, for example, alumina ceramic, lowtemperature co-fired ceramic and other various ceramics, as well asprinted circuit boards utilizing organic (plastic) substrate materials.Accordingly, the OLED display industry is now trying to adopt a standardof using only ceramic substrates, as well as adding special treatment,to reduce the warpage level down to within half of the industryspecification.

[0033] Unfortunately, adoption of the standard proposed by themanufacturers of flat screen devices will significantly increasesubstrate cost. In addition, substrate development work will also berequired. Consequently, in order to comply with the coplanarityspecification requirements for substrates utilized within OLED displays,one embodiment includes a process for compensation of substrate warpage,for example, as depicted in FIGS. 4A-4C.

[0034] Referring now to FIG. 4A, substrate 410 is selected, which has anundesirably high warpage level. As a result, a substrate coplanaritylevel of the surface of substrate 410 generally exceeds the maximumcoplanarity specification value of, for example, 30 microns per inch.Therefore, in accordance with one embodiment, conductive bumps 420 areformed upon an area of substrate 410. In one embodiment, conductivebumps 420 may be formed onto electrode pads of substrate 410 (notshown).

[0035] In one embodiment, the conductive bumps 420 are generallyconfigured as soft bumps, which require electrical conductivity, as wellas deformation characteristics at a certain temperature. In oneembodiment, the conductive bumps may have a diameter within the range of50 μm to 300 μm depending on the desired resolution. In one embodiment,the electrode pads are comprised of a material including ITO, Aluminumpad with gold flash plating, or electric pads with Ni/Au plating or Snplating.

[0036] Accordingly, the soft bumps may be comprised of a materialincluding various metals, such as solder bumps, as well as conductiveplastic-elastic materials, such as, but not limited to Pb/Sn alloy Au,conductive rubber, and the like. Once conductive bumps 420 are formedupon substrate 410, hot coining/stamping tool 430 may be applied toconductive bumps 420. As such, in embodiment depicted in FIG. 4B, a hotcoining/stamping tool 430 is applied to conductive bumps 420. Onceapplied, hot coining/stamping tool 430 will cause the formation of avirtual plane (surface) 440 over the soft bumps, for example, asdepicted in FIG. 4C. In general, a tool with up/down stroke motion withsome dead weight control may be used as tool 430. Precise alignment isgenerally not required, since bump coining is performed for a desiredarea.

[0037] In the embodiments depicted, the virtual surface 440 will have acoplanarity level, which at most is equal to the coplanarityspecification requirement value of, for example, 30 microns per inch.Accordingly, after coining/stamping conductive bumps 420, virtualsurface 440 is formed, which has an acceptable coplanarity level. Assuch, virtual surface 440 enables the formation of warpage compensatedsubstrate 400, as depicted in FIG. 4C. Consequently, utilizing thewarpage compensated substrate, an OLED display panel module assembly maybe formed utilizing a substrate, which initially fails to meet thecoplanarity specification requirement.

[0038]FIG. 5 depicts the formation of an OLED display panel moduleassembly utilizing warpage compensated substrate 400 of FIG. 4. Asillustrated, OLED structure 200, for example, as depicted in FIG. 2,will include electrode 240. Electrode 240 generally requires a currentsource to generate light output 470. As such, in accordance with oneembodiment, a conductive adhesive layer 460 of, for example, Pb/Snconductive layer, is formed onto the virtual surface 440 and overelectrode pad 450.

[0039] Consequently, utilizing conductive adhesive layer 460, anelectronic connection is formed between electrode pad 450 and OLEDelectrode 240 to enable application of a voltage potential betweensubstrate 410 and OLED structure 200 to generate light output 470. Assuch, an OLED display panel module assembly is generated in accordancewith the embodiment depicted in FIG. 5 to generate light output 470 andmay be used to form a flat panel display television or screen, forexample as depicted in FIG. 1.

[0040]FIG. 6 depicts OLED display panel module 500 formed utilizingwarpage compensated substrate 400, in accordance with a furtherembodiment. As illustrated, the OLED display panel module 500 includeswarpage compensated substrate 400 having substrate electrode pads 450and adhesive contact 460. The adhesive contact 460 enables electronicconnection between the electrodes 450 and (red/blue/green (R/G/B)) LED520. The OLED includes glass substrate 510, including an indium-tinoxide (ITO) anode rail 530, as well as aluminum (Al) cathode rail 540,as well as passivation layer 512. In one embodiment, the passivationoverlies cathold rail 540 and protective layer 522 of, for example,silicon dioxide (SiO₂) polyamide disposed between a passivation layer512 and warpage compensation substrate 400.

[0041] In addition, conductive adhesive contact 560 is utilized toprovide an electronic connection between substrate electrode pad 450 andAl cathode rail 540 to provide a voltage potential to LED 520. As such,in accordance with one embodiment, an OLED display panel module assembly500 is generated with red LED 520, green LED 520, as well as blue LED520 to form an OLED display panel cell. As such, utilizing anycombination of red, blue or green, a plurality of OLED display panelcells may be formed within a flat panel display device to generate adesired image.

[0042] Accordingly, utilizing embodiments described herein, an OLEDdisplay panel module assembly 500 may be formed utilizing conventionalsubstrates, which have substandard warpage levels. Therefore, bycompensating warpage levels of various substrates, an OLED display panelmodule assembly, as well as an OLED display panel cells are formed at alower cost than conventional means. Consequently, flat panel displayscreen, may be manufactured at drastically lowered costs by utilizingOLED display panel module assemblies described according to embodimentsof the present invention.

[0043] Operation

[0044]FIG. 7 depicts a flowchart illustrating method 600 for warpagecompensation of substrate in order to enable usage of a substrate withinan OLED display panel module assembly in accordance with one embodiment.Accordingly, at process block 602, a substrate is selected having acoplanarity level in excess of a maximum coplanarity specification leveldue to warpage of the substrate. As indicated above, substratestraditionally used within the semiconductor industry, such as aluminaceramic, low temperature co-fired ceramic and other various ceramics, aswell as printed circuit boards utilizing organic/(plastic) substratematerials. These substrates generally exhibit significant warpagelevels, which may be in the range of 60 micrometers per inch through 700micrometers per inch.

[0045] Once the substrate is selected, a plurality of conductive bumpsare formed over an area of the substrate, at process block 604. In oneembodiment, the conductive bumps are comprised of a material, whichincludes electric conductivity as well as deformation characteristics atcertain temperatures. In one embodiment, solder bumps (e.g., lead-tinsolder bumps) may be utilized; however, the conductive bumps include,but are not limited to, conductive, plastic-elastic materials, such assynthetic polymers (plastics) including rubber, or the like. Finally, atprocess block 620, a thermal process is applied to the plurality ofconductive bumps to obtain a virtual surface over the conductive bumps,having at most a coplanarity level equal to the maximum coplanarityspecification level to thereby compensate for warpage of the selectedsubstrate.

[0046]FIG. 8 depicts a flowchart illustrating an additional method 632for forming of an OLED display panel module assembly utilizing thewarpage compensated substrate, formed in accordance with method 600, asdepicted in FIG. 7. At process block 634, a conductive adhesive isapplied as a planar layer over the virtual surface of the plurality ofconductive bumps. Once applied, electrodes between an OLED panel and theselected substrate are connected via the conductive adhesive material,using, for example, screen printing onto glass substrate 510 to providethe connection. For example, as depicted with reference to FIG. 5, OLEDelectrode 240 is connected with electrode pad 450 via conductiveadhesive layer 460. Once such connection is formed, the substrate mayapply a voltage potential via electrode pad 450 to electrode 240 inorder to generate light output 470 via OLED structure 200.

[0047]FIG. 9 depicts a flowchart illustrating an additional method 606for forming the conductive bumps of process block 604, as depicted inFIG. 7. At process block 608, one or more electrode pads of the selectedsubstrate are determined. Once determined, at process block 610, theconductive bumps are formed over the electrode pads of the selectedsubstrate. In one embodiment, the conductive bumps may be comprised ofany material which provides electrical conductivity, as well ascontaining a deformation characteristic at a certain temperature.Accordingly, the soft bumps may be made of any metal, such as forexample, solder, as well as conductive plastic-elastic materials, suchas synthetic polymers (plastics), including, but not limited to, rubber.In one embodiment, when the conductive bumps are comprised of solder,the connection between the OLED electrode and the substrate electrodepads may be performed via solder joint interconnection.

[0048]FIG. 10 depicts a flowchart illustrating an additional method 622for applying the thermal process of process block 620, as depicted inFIG. 7 and in accordance with the further embodiment of the presentinvention. As such, at process block 624, the substrate is placed intoalignment within a coining/stamping device. Next, at process block 626,it is determined whether the substrate bumps are aligned with the tool.Once aligned, at process block 628, hot coining/stamping is performedover the plurality of conductive bumps to form the virtual surface, forexample, as depicted in FIGS. 4B and 4C.

[0049] Accordingly, the virtual surface will have a nearly perfectcoplanarity level and certainly a coplanarity level, which is at most,equal to the maximum coplanarity specification level. As such, by usinghot coining or stamping over the conductive bumps, the coplanarity ofthe formed virtual surface compensates for the warpage of the selectedsubstrate. Accordingly, utilizing embodiments of the present invention,conventional substrate materials may be utilized within OLED displaypanel modules without having to undergo special treatments to theselected substrate to compensate for the warpage or spending significantcapital for ceramics which comply with coplanarity specification valuerequirements.

[0050] Consequently, utilizing embodiments of the present invention,OLED display panel modules assembly may be formed at drastically lowercosts. As such, OLED display panel cells of R/G/B LEDs display panelmodules assemblies may be utilized to form flat panel displays with fullcolor and full motion, including a level of brightness and sharpness notpossible with traditional devices. Likewise, interconnection systems forOLED display devices may select from a vast variety of substratematerials, including for example, thin film substrates to utilize withinthe OLED display panel module assembly process.

ALTERNATE EMBODIMENTS

[0051] Several aspects of one implementation of the OLED display panelmodule assembly utilizing a warpage compensated substrate have beendescribed. However, various implementations of the warpage compensationprovide numerous features including, complementing, supplementing,and/or replacing the features described above. Features can beimplemented as part of any assembly having strict coplanarityrequirements in different embodiment implementations. In addition, theforegoing description, for purposes of explanation, used specificnomenclature to provide a thorough understanding of the embodimentspresented. However, it will be apparent to one skilled in the art thatthe specific details are not required in order to practice theembodiments.

[0052] In addition, although an embodiment described herein is directedto a OLED display panel module assembly, it will be appreciated by thoseskilled in the art that the embodiments can be applied to other systems.In fact, systems for warpage compensation fall within the embodiments,as defined by the appended claims. The embodiments described above werechosen and described in order to best explain the principles of theembodiments and its practical applications. These embodiments werechosen to thereby enable others skilled in the art to best utilize thevarious embodiments with various modifications as are suited to theparticular use contemplated.

[0053] It is to be understood that even though numerous characteristicsand advantages of various embodiments have been set forth in theforegoing description, together with details of the structure andfunction of various embodiments, this disclosure is illustrative only.In some cases, certain subassemblies are only described in detail withone such embodiment. Nevertheless, it is recognized and intended thatsuch subassemblies may be used in other embodiments. Changes may be madein detail, especially matters of structure and management of partswithin the principles of the embodiments to the full extent indicated bythe broad general meaning of the terms in which the appended claims areexpressed.

[0054] Having disclosed exemplary embodiments and the best mode,modifications and variations may be made to the disclosed embodimentswhile remaining within the scope of the embodiments as defined by thefollowing claims.

What is claimed is:
 1. A method comprising: selecting a substrate havinga surface coplanarity level in excess of a maximum coplanarityspecification level; forming a plurality of conductive bumps over anarea of the selected substrate surface; and forming a virtual surfaceover the conductive bumps, having at most a coplanarity level equal tothe maximum coplanarity specification level to compensate for thesubstrate warpage.
 2. The method of claim 1, further comprising:applying a conductive adhesive over the virtual surface formed over theplurality of conductive bumps; and connecting electrodes between an OLEDpanel and the selected substrate via the conductive adhesive layer. 3.The method of claim 1, wherein the maximum coplanarity specificationlevel equals 30 micros per inch and a substrate warpage level of theselected substrate is within the range of 60 micros per inch through 700micros per inch.
 4. The method of claim 1, wherein the selectedsubstrate is comprised of a material selected from one of aluminaceramic, low-temperature co-fired ceramic, organic material and plasticmaterial.
 5. The method of claim 1, wherein forming the conductive bumpsfurther comprises: determining one or more electrode pads of theselected substrate; and forming the conductive bumps over the determinedelectrode pads of the selected substrate.
 6. The method of claim 1,wherein forming the virtual surface further comprises: placing thesubstrate into alignment with a coining/stamping device; hotcoining/stamping over the plurality of substrate bumps to form thevirtual surface having a coplanarity at most equal to the maximumcoplanarity specification level, such that the coplanarity of thevirtual surface compensates for warpage of the selected substrate. 7.The method of claim 1, wherein the conductive bumps are comprised of oneof a conductive metal and a conductive, plastic elastic material.
 8. Themethod of claim 1, wherein the conductive bumps are comprised of rubber.9. The method of claim 2, wherein connecting further comprises:connecting an OLED panel electrode to substrate electrode pads of theselected substrate via the conductive adhesive layer formed over thevirtual surface of the plurality of conductive bumps.
 10. The method ofclaim 9, wherein the OLED electrode is connected to substrate electrodepads via solder joint interconnection.